Homogeneous charge compression ignition information
Form of internal combustion
Homogeneous Charge Compression Ignition (HCCI) is a form of internal combustion in which well-mixed fuel and oxidizer (typically air) are compressed to the point of auto-ignition. As in other forms of combustion, this exothermic reaction produces heat that can be transformed into work in a heat engine.
HCCI combines characteristics of conventional gasoline engine and diesel engines. Gasoline engines combine homogeneous charge (HC) with spark ignition (SI), abbreviated as HCSI. Modern direct injection diesel engines combine stratified charge (SC) with compression ignition (CI), abbreviated as SCCI.
As in HCSI, HCCI injects fuel during the intake stroke. However, rather than using an electric discharge (spark) to ignite a portion of the mixture, HCCI raises density and temperature by compression until the entire mixture reacts spontaneously.
Stratified charge compression ignition also relies on temperature and density increase resulting from compression. However, it injects fuel later, during the compression stroke. Combustion occurs at the boundary of the fuel and air, producing higher emissions, but allowing a leaner and higher compression burn, producing greater efficiency.
Controlling HCCI requires microprocessor control and physical understanding of the ignition process. HCCI designs achieve gasoline engine-like emissions with diesel engine-like efficiency.
HCCI engines achieve extremely low levels of oxides of nitrogen emissions (NO x) without a catalytic converter. Hydrocarbons (unburnt fuels and oils) and carbon monoxide emissions still require treatment to meet automobile emissions control regulations.
Recent research has shown that the hybrid fuels combining different reactivities (such as gasoline and diesel) can help in controlling HCCI ignition and burn rates. RCCI, or reactivity controlled compression ignition, has been demonstrated to provide highly efficient, low emissions operation over wide load and speed ranges.[1]
^"College of Engineering @ The University of Wisconsin-Madison, initiatives in energy, health, nanotechnology, security, and information technology". Engr.wisc.edu. Archived from the original on 2010-02-25. Retrieved 2014-03-31.
and 25 Related for: Homogeneous charge compression ignition information
HomogeneousChargeCompressionIgnition (HCCI) is a form of internal combustion in which well-mixed fuel and oxidizer (typically air) are compressed to...
engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel...
traditionally the compression stroke, the charge is partially expelled back out through the still-open intake valve. Typically, this loss of charge air would...
transmission DeAct: Cylinder deactivation dHCCI: Diesel homogeneouschargecompressionignition DMV: California Department of Motor Vehicles DOHC: Dual...
preignition (or "knocking") if compression ratio is increased, but improvements such as laser ignition or microwave enhanced ignition might help prevent knocking...
cycles can be classified as vapor compression, vapor absorption, gas cycle, or Stirling cycle types. The vapor-compression cycle is used by many refrigeration...
Torino 2008, GM Powertrain Europe announced the ignition-less HCCI (HomogeneousChargeCompressionIgnition) mode of the direct injection version of 2.2...
thermodynamic cycle that describes the functioning of a typical spark ignition piston engine. It is the thermodynamic cycle most commonly found in automobile...
\Delta S_{C}<0} because the isothermal compression decreases the multiplicity of the gas. Isentropic compression. (4 to 1 on Figure 1, D to A on Figure...
Skyactiv-X is the first commercial petrol engine to use homogeneouschargecompressionignition (HCCI), in which the fuel-air mixture ignites spontaneously...
to operate at higher compression ratios. If a petrol engine were to have the same compression ratio, then knocking (self-ignition) would occur and this...
with its compressionignition cannot be used in a practical Wankel engine. Therefore, Wankel engines typically have a high-voltage spark ignition system...
homogeneouscharge: a homogeneous mixture of air and fuel, which is ignited by a spark plug at a predetermined moment near the top of the compression...
the cylinder. A small piston fuel pump injects liquid during compression. The ignition source was likely a hot tube as in Atkinson's other engines. This...
in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within...
David 2007 Preheating; pp. 406–410, Advancement of Ignition Timing: pp. 404, 417-18, 530 Higher Compression with Ethanolpp. 70, 358-60, 415-19,429, 433-435...
cycle (the name "Rankine" cycle is used only for the ideal cycle), the compression by the pump and the expansion in the turbine are not isentropic. In other...